From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id 681B06B0253 for ; Thu, 2 Nov 2017 05:09:55 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id v105so2619204wrc.11 for ; Thu, 02 Nov 2017 02:09:55 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id 90sor1102188wrl.59.2017.11.02.02.09.53 for (Google Transport Security); Thu, 02 Nov 2017 02:09:54 -0700 (PDT) Date: Thu, 2 Nov 2017 12:09:51 +0300 From: "Kirill A. Shutemov" Subject: Re: [alsa-devel] BUG: soft lockup Message-ID: <20171102090951.drjf7wc2urcmtla5@node.shutemov.name> References: <94eb2c19df188b1926055cf13c21@google.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="xqvwsu7vpwjsljlm" Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Takashi Iwai Cc: Dmitry Vyukov , syzbot , aaron.lu@intel.com, alsa-devel@alsa-project.org, Michal Hocko , Jan Kara , Minchan Kim , Peter Zijlstra , ying.huang@intel.com, syzkaller-bugs@googlegroups.com, LKML , linux-mm@kvack.org, Takashi Iwai , "Aneesh Kumar K.V" , shli@fb.com, David Rientjes , Stephen Rothwell , Andrew Morton , zi.yan@cs.rutgers.edu, Matthew Wilcox , "Kirill A. Shutemov" --xqvwsu7vpwjsljlm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Nov 02, 2017 at 09:23:58AM +0100, Takashi Iwai wrote: > > Currently the least ALSA timer interrupt period is limited to 1ms. > Does it still too much? > > Can the reproducer triggers it reliably? If yes, could you forward > it, too (and config as well), so that I'll try to dig down more exact > code paths? All of that is part of original report: http://lkml.kernel.org/r/94eb2c19df188b1926055cf13c21@google.com marc.info hasn't stored repro.c for some reasone. Attached. I've just check it reproduces reliably for me in KVM. I also checked that it's not specific to THP -- still trigirable with huge pages disabled. -- Kirill A. Shutemov --xqvwsu7vpwjsljlm Content-Type: text/x-c; charset=us-ascii Content-Disposition: attachment; filename="repro.c" // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } static void test(); void loop() { while (1) { test(); } } long r[64]; void test() { memset(r, -1, sizeof(r)); r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul, 0xfffffffffffffffful, 0x0ul); memcpy((void*)0x203a2000, "\x2e\x2f\x66\x69\x6c\x65\x30\x00", 8); *(uint64_t*)0x20000fe0 = (uint64_t)0x0; *(uint64_t*)0x20000fe8 = (uint64_t)0x2710; *(uint64_t*)0x20000ff0 = (uint64_t)0x77359400; *(uint64_t*)0x20000ff8 = (uint64_t)0x0; r[6] = syscall(__NR_utimes, 0x203a2000ul, 0x20000fe0ul); r[7] = syscall(__NR_getdents64, 0xfffffffffffffffful, 0x2076e000ul, 0x0ul); memcpy((void*)0x20c67ff1, "\x2f\x64\x65\x76\x2f\x73\x6e\x64\x2f\x74\x69\x6d\x65\x72\x00", 15); r[9] = syz_open_dev(0x20c67ff1ul, 0x0ul, 0x0ul); *(uint32_t*)0x205a3fcc = (uint32_t)0x0; *(uint32_t*)0x205a3fd0 = (uint32_t)0x2; *(uint32_t*)0x205a3fd4 = (uint32_t)0x0; *(uint32_t*)0x205a3fd8 = (uint32_t)0xffffffffffffffff; *(uint32_t*)0x205a3fdc = (uint32_t)0x0; *(uint8_t*)0x205a3fe0 = (uint8_t)0x0; *(uint8_t*)0x205a3fe1 = (uint8_t)0x0; *(uint8_t*)0x205a3fe2 = (uint8_t)0x0; *(uint8_t*)0x205a3fe3 = (uint8_t)0x0; *(uint8_t*)0x205a3fe4 = (uint8_t)0x0; *(uint8_t*)0x205a3fe5 = (uint8_t)0x0; *(uint8_t*)0x205a3fe6 = (uint8_t)0x0; *(uint8_t*)0x205a3fe7 = (uint8_t)0x0; *(uint8_t*)0x205a3fe8 = (uint8_t)0x0; *(uint8_t*)0x205a3fe9 = (uint8_t)0x0; *(uint8_t*)0x205a3fea = (uint8_t)0x0; *(uint8_t*)0x205a3feb = (uint8_t)0x0; *(uint8_t*)0x205a3fec = (uint8_t)0x0; *(uint8_t*)0x205a3fed = (uint8_t)0x0; *(uint8_t*)0x205a3fee = (uint8_t)0x0; *(uint8_t*)0x205a3fef = (uint8_t)0x0; *(uint8_t*)0x205a3ff0 = (uint8_t)0x0; *(uint8_t*)0x205a3ff1 = (uint8_t)0x0; *(uint8_t*)0x205a3ff2 = (uint8_t)0x0; *(uint8_t*)0x205a3ff3 = (uint8_t)0x0; *(uint8_t*)0x205a3ff4 = (uint8_t)0x0; *(uint8_t*)0x205a3ff5 = (uint8_t)0x0; *(uint8_t*)0x205a3ff6 = (uint8_t)0x0; *(uint8_t*)0x205a3ff7 = (uint8_t)0x0; *(uint8_t*)0x205a3ff8 = (uint8_t)0x0; *(uint8_t*)0x205a3ff9 = (uint8_t)0x0; *(uint8_t*)0x205a3ffa = (uint8_t)0x0; *(uint8_t*)0x205a3ffb = (uint8_t)0x0; *(uint8_t*)0x205a3ffc = (uint8_t)0x0; *(uint8_t*)0x205a3ffd = (uint8_t)0x0; *(uint8_t*)0x205a3ffe = (uint8_t)0x0; *(uint8_t*)0x205a3fff = (uint8_t)0x0; r[47] = syscall(__NR_ioctl, r[9], 0x40345410ul, 0x205a3fccul); r[48] = syscall(__NR_ioctl, r[9], 0x54a2ul); memcpy((void*)0x20bd8000, "\x2f\x64\x65\x76\x2f\x73\x65\x71\x75\x65\x6e\x63\x65\x72\x32" "\x00", 16); r[50] = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20bd8000ul, 0x101000ul, 0x0ul); *(uint32_t*)0x20d1e000 = (uint32_t)0xffffffffffffffff; *(uint32_t*)0x20d1e004 = (uint32_t)0x730e; *(uint32_t*)0x20d1e008 = (uint32_t)0x7; *(uint32_t*)0x20d1e00c = (uint32_t)0x3; *(uint8_t*)0x20d1e010 = (uint8_t)0xffffffffffffffff; *(uint8_t*)0x20d1e011 = (uint8_t)0x80000001; *(uint8_t*)0x20d1e012 = (uint8_t)0x4610; *(uint8_t*)0x20d1e013 = (uint8_t)0x9; *(uint32_t*)0x20d1e014 = (uint32_t)0x8; *(uint32_t*)0x20d1e018 = (uint32_t)0x9; *(uint32_t*)0x20d1e01c = (uint32_t)0x7; *(uint32_t*)0x20d1e020 = (uint32_t)0x1; r[63] = syscall(__NR_ioctl, r[50], 0x5402ul, 0x20d1e000ul); } int main() { int i; for (i = 0; i < 8; i++) { if (fork() == 0) { loop(); return 0; } } sleep(1000000); return 0; } --xqvwsu7vpwjsljlm-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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